Regulatory Requirements (Net Capital and Net Capital Requirements for Schwab and optionsXpress, Inc) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schwab [Member]
Compliance with Regulatory Capital Requirements for Broker Dealers [Line Items]
Net Capital	$ 1,974,000	$ 1,846,000
Minimum Net Capital Required	250	250
2% of Aggregate Debit Balances	394,000	355,000
Net Capital in Excess of Required Capital	1,580,000	1,491,000
OptionsXpress [Member]
Compliance with Regulatory Capital Requirements for Broker Dealers [Line Items]
Net Capital	295,000	269,000
Minimum Net Capital Required	1,000	1,000
2% of Aggregate Debit Balances	7,000	8,000
Net Capital in Excess of Required Capital	$ 288,000	$ 261,000